Obesity is a complex medical disorder of appetite regulation and metabolism resulting in excessive accumulation of adipose tissue mass. Typically defined as a body mass index (BMI) of 30 kg/m2 or more, obesity is a world-wide public health concern that is associated with cardiovascular disease, diabetes, certain cancers, respiratory complications, osteoarthritis, gallbladder disease, decreased life expectancy, and work disability. The primary goals of obesity therapy are to reduce excess body weight, improve or prevent obesity-related morbidity and mortality, and maintain long-term weight loss.
Treatment modalities typically include lifestyle management, pharmacotherapy, and surgery. Treatment decisions are made based on severity of obesity, seriousness of associated medical conditions, patient risk status, and patient expectations. Notable improvements in cardiovascular risk and the incidence of diabetes have been observed with weight loss of 5-10% of body weight, supporting clinical guidelines for the treatment of obesity that recommend a target threshold of 10% reduction in body weight from baseline values.
However, while prescription anti-obesity medications are typically considered for selected subjects at increased medical risk because of their weight and for whom lifestyle modifications (diet restriction, physical activity, and behavior therapy) alone have failed to produce durable weight loss, approved drugs have had unsatisfactory efficacy for severely obese subjects, leading to only ˜3-5% reduction in body weight after a year of treatment.
Bariatric surgery may be considered as a weight loss intervention for subjects at or exceeding a BMI of 40 kg/m2. Subjects with a BMI≧35 kg/m2 and an associated serious medical condition are also candidates for this treatment option. Unfortunately, postoperative complications commonly result from bariatric surgical procedures, including bleeding, embolism or thrombosis, wound complications, deep infections, pulmonary complications, and gastrointestinal obstruction; reoperation during the postoperative period is sometimes necessary to address these complications. Rates of reoperation or conversion surgery beyond the postoperative period depend on the type of bariatric procedure, and in one study ranged from 17% to 31%. Intestinal absorptive abnormalities, such as micronutrient deficiency and protein-calorie malnutrition, also are typically seen with bypass procedures, requiring lifelong nutrient supplementation. Major and serious adverse outcomes associated with bariatric surgery are common, observed in approximately 4 percent of procedures performed (including death in 0.3 to 2 percent of all patients receiving laparoscopic banding or bypass surgeries, respectively).
MetAP2 encodes a protein that functions at least in part by enzymatically removing the amino terminal methionine residue from certain newly translated proteins such as glyceraldehyde-3-phosphate dehydrogenase (Warder et al. (2008) J Proteome Res 7:4807). Increased expression of the MetAP2 gene has been historically associated with various forms of cancer. Molecules inhibiting the enzymatic activity of MetAP2 have been identified and have been explored for their utility in the treatment of various tumor types (Wang et al. (2003) Cancer Res. 63:7861) and infectious diseases such as microsporidiosis, leishmaniasis, and malaria (Zhang et al. (2002) J. Biomed. Sci. 9:34). However, such MetAP2 inhibitors may be useful as well for subjects with excess adiposity and conditions related to adiposity including type 2 diabetes, hepatic steatosis, and cardiovascular disease (via e.g. ameliorating insulin resistance, reducing hepatic lipid content, and reducing cardiac workload). Methods of treating obese subjects that are more effective than e.g. dieting alone are clearly needed.